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Clear NAN when reading back a global range if necessary.

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When reading back from the global store, we must clear the NAN bit if
necessary.  The reason it's not happening is because the constructor
sets a NAN by default (when HONOR_NANS).  We must be careful to clear
the NAN bit if the original range didn't have a NAN.

I have commented the reason we use the constructor instead of filling
out the fields by hand, because it wasn't clear at re-reading this
code.

	PR 107569/tree-optimization

gcc/ChangeLog:

	* value-range-storage.cc (frange_storage_slot::get_frange): Clear
	NAN if appropriate.
	* value-range.cc (range_tests_floats): New test.
This commit is contained in:
Aldy Hernandez 2022-11-09 16:05:08 +01:00
parent 8bb3f172d3
commit 4eadbe8006
2 changed files with 17 additions and 1 deletions
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9
gcc/value-range-storage.cc
View file

@ -276,13 +276,20 @@ frange_storage_slot::get_frange (frange &r, tree type) const
return;
}
// Use the constructor because it will canonicalize the range.
// We use the constructor to create the new range instead of writing
// out the bits into the frange directly, because the global range
// being read may be being inlined into a function with different
// restrictions as when it was originally written. We want to make
// sure the resulting range is canonicalized correctly for the new
// consumer.
r = frange (type, m_min, m_max, m_kind);
// The constructor will set the NAN bits for HONOR_NANS, but we must
// make sure to set the NAN sign if known.
if (HONOR_NANS (type) && (m_pos_nan ^ m_neg_nan) == 1)
r.update_nan (m_neg_nan);
else if (!m_pos_nan && !m_neg_nan)
r.clear_nan ();
}
bool

9
gcc/value-range.cc
View file

@ -4051,6 +4051,15 @@ range_tests_floats ()
ASSERT_TRUE (real_isinf (&r0.lower_bound (), true));
ASSERT_TRUE (real_isinf (&r0.upper_bound (), true));
}
// Test that reading back a global range yields the same result as
// what we wrote into it.
tree ssa = make_temp_ssa_name (float_type_node, NULL, "blah");
r0.set_varying (float_type_node);
r0.clear_nan ();
set_range_info (ssa, r0);
get_global_range_query ()->range_of_expr (r1, ssa);
ASSERT_EQ (r0, r1);
}
// Run floating range tests for various combinations of NAN and INF